KR20210142542A - Method and apparatus for handling sidelink operation in wireless communication system - Google Patents

Abstract

The present invention relates to a method for handling a sidelink operation in a wireless communication system to handle control information required for sidelink data transmission/reception in a discontinuous reception (DRX) mode and an apparatus thereof. According to the present invention, an operation method of a first in a wireless communication system comprises the following steps: monitoring a physical downlink control channel (PDCCH) transmitted from a base station in an active time related to DRX, wherein the first terminal is in an RRC connection state and the DRX is set to the first terminal; detecting information related to a sidelink resource allocated by the base station on the basis of a monitoring result of the PDCCH; identifying whether the sidelink resource is a resource for new transmission of a sidelink signal or a resource for retransmission of the sidelink signal; when the sidelink resource is the resource for retransmission of the sidelink signal, identifying whether sidelink HARQ feedback is activated for a sidelink HARQ process of the first terminal; when the sidelink HARQ feedback is enabled, receiving sidelink HARQ feedback information for the sidelink signal transmitted from the first terminal to the second terminal from the second terminal; and reporting the received sidelink HARQ feedback information to the base station.

Description

METHOD AND APPARATUS FOR HANDLING SIDELINK OPERATION IN WIRELESS COMMUNICATION SYSTEM

The present disclosure relates to a wireless communication system, and more particularly, to a method and apparatus for handling a sidelink operation in a wireless communication system.

4G (4 ^th generation) to meet the traffic demand in the radio data communication system increases since the commercialization trend, efforts to develop improved 5G (5 ^th generation) communication system, or pre-5G communication system have been made. For this reason, the 5G communication system or the pre-5G communication system is called a 4G network after (Beyond 4G Network) communication system or an LTE (Long Term Evolution) system after (Post LTE) system.

In order to achieve high data rates, 5G communication systems are being considered for implementation in very high frequency (mmWave) bands (eg, 60 gigabytes (60 GHz) bands). In order to mitigate the path loss of radio waves and increase the propagation distance of radio waves in the ultra-high frequency band, in the 5G communication system, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) are used. ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed.

In addition, for network improvement of the system, in the 5G communication system, an evolved small cell, an advanced small cell, a cloud radio access network (cloud RAN), an ultra-dense network (ultra-dense network) , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and reception interference cancellation Technology development is underway.

In addition, in the 5G system, Hybrid Frequency Shift Keying and Quadrature Amplitude Modulation (FQAM) and Sliding Window Superposition Coding (SWSC), which are advanced coding modulation (Advanced Coding Modulation, ACM) methods, and Filter Bank Multi Carrier (FBMC), an advanced access technology, ), Non Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA) are being developed.

On the other hand, the Internet is evolving from a human-centered connection network where humans create and consume information to an Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. Internet of Everything (IoE) technology, which combines big data processing technology through connection with cloud servers, etc. with IoT technology, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. , M2M), and MTC (Machine Type Communication) are being studied. In the IoT environment, an intelligent IT (Internet Technology) service that collects and analyzes data generated from connected objects and creates new values in human life can be provided. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, advanced medical service, etc. can be applied to

Accordingly, various attempts are being made to apply the 5G communication system to the IoT network. For example, technologies such as sensor network, machine to machine (M2M), and MTC (Machine Type Communication) are implemented by 5G communication technologies such as beamforming, MIMO, and array antenna. will be. The application of a cloud radio access network (cloud RAN) as the big data processing technology described above is an example of the convergence of 5G technology and IoT technology.

In addition, terminal direct communication (sidelink communication) using a 5G communication system is being studied, and the terminal direct communication is applied to, for example, vehicle-to-everything (hereinafter 'V2X') to provide various services to users. It is expected to be able to provide.

SUMMARY This disclosure provides an apparatus and method for handling sidelink operations in a wireless communication system.

In addition, the present disclosure provides an apparatus and method for processing control information required for sidelink data transmission/reception in a discontinuous reception mode (DRX) of a terminal of a wireless communication system.

In addition, the present disclosure provides an apparatus and method for processing control information necessary for transmitting and receiving sidelink data in BWP (bandwidth part) deactivation of a terminal in a wireless communication system.

According to an embodiment of the present disclosure, in a method of operating a first terminal in a wireless communication system, the first terminal is in a radio resource control (RRC) connection state, a discontinuous reception (DRX) is set to the first terminal, Monitoring a physical downlink control channel (PDCCH) transmitted from a base station in an active time related to the DRX when the sidelink resource allocation mode 1 is configured for the first terminal, based on the monitoring of the PDCCH , detecting information related to a sidelink resource allocated by the base station, identifying whether the sidelink resource is a resource for new transmission of a sidelink signal or a resource for retransmission of the sidelink signal; When the sidelink resource is a resource for retransmission of the sidelink signal, identifying whether sidelink HARQ feedback is activated for a sidelink hybrid automatic repeat request (HARQ) process of the first terminal, the side When link HARQ feedback is activated, receiving sidelink HARQ feedback information for a sidelink signal transmitted from the first terminal to a second terminal from a second terminal, and receiving the received sidelink HARQ feedback information from the base station and, in response to the report, starting a sidelink HARQ round trip time (RTT) timer related to the DRX.

According to an embodiment of the present disclosure, in a wireless communication system, a first terminal, a transceiver, and the first terminal are in a radio resource control (RRC) connection state, and discontinuous reception (DRX) is set to the first terminal, and , when sidelink resource allocation mode 1 is configured for the first terminal, monitoring a physical downlink control channel (PDCCH) transmitted from a base station in an active time related to the DRX, and monitoring the PDCCH , detects information related to a sidelink resource allocated by the base station, identifies whether the sidelink resource is a resource for new transmission of a sidelink signal or a resource for retransmission of the sidelink signal, and When the link resource is a resource for retransmission of the sidelink signal, it is identified whether sidelink HARQ feedback is activated for the sidelink hybrid automatic repeat request (HARQ) process of the first terminal, and the sidelink HARQ feedback is activated, the sidelink HARQ feedback information for the sidelink signal transmitted from the first terminal to the second terminal is received from the second terminal through the transceiver, and the received sidelink information is received from the second terminal through the transceiver. and reporting HARQ feedback information to the base station and starting a sidelink HARQ round trip time (RTT) timer related to the DRX in response to the report.

1 illustrates a wireless communication system according to an embodiment of the present disclosure.
2 illustrates a configuration of a base station in a wireless communication system according to an embodiment of the present disclosure.
3 illustrates a configuration of a terminal in a wireless communication system according to an embodiment of the present disclosure.
4 illustrates a configuration of a communication unit in a wireless communication system according to an embodiment of the present disclosure.
5 illustrates a structure of a radio time-frequency resource of a wireless communication system according to an embodiment of the present disclosure.
6A is a diagram illustrating a scenario for sidelink communication according to an embodiment of the present disclosure.
6B is a diagram illustrating a scenario for sidelink communication according to an embodiment of the present disclosure.
6C is a diagram illustrating a scenario for sidelink communication according to an embodiment of the present disclosure.
6D is a diagram illustrating a scenario for sidelink communication according to an embodiment of the present disclosure.
7A is a diagram for explaining a transmission method of sidelink communication according to an embodiment of the present disclosure.
7B is a diagram for explaining a transmission method of sidelink communication according to an embodiment of the present disclosure.
8 is a diagram illustrating an operation in which a terminal processes sidelink resource allocation information in a discontinuous reception mode (DRX mode) according to an embodiment of the present disclosure.
9 is a diagram illustrating an operation in which a terminal processes sidelink resource allocation information in a discontinuous reception mode according to an embodiment of the present disclosure.
10 is a diagram illustrating an operation in which a terminal processes sidelink resource allocation information in a discontinuous reception mode according to an embodiment of the present disclosure.
11 is a diagram illustrating an operation in which a terminal processes sidelink resource allocation information in a discontinuous reception mode according to an embodiment of the present disclosure.
12A is a diagram illustrating an operation in which a terminal processes sidelink resource allocation information in a discontinuous reception mode according to an embodiment of the present disclosure.
12B is a diagram illustrating an operation in which a terminal processes sidelink resource allocation information in a discontinuous reception mode according to an embodiment of the present disclosure.

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. At this time, it should be noted that in the accompanying drawings, the same components are denoted by the same reference numerals as much as possible. In addition, detailed descriptions of well-known functions and configurations that may obscure the gist of the present disclosure will be omitted.

In describing embodiments in the present specification, descriptions of technical contents that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to more clearly convey the gist of the present disclosure without obscuring the gist of the present disclosure by omitting unnecessary description.

For the same reason, some components are exaggerated, omitted, or schematically illustrated in the accompanying drawings. In addition, the size of each component does not fully reflect the actual size. In each figure, the same or corresponding elements are assigned the same reference numerals.

Advantages and features of the present disclosure, and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the present embodiments allow the disclosure of the present disclosure to be complete, and common knowledge in the art to which the present disclosure pertains. It is provided to fully inform those who have the scope of the disclosure, and the present disclosure is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

At this time, it will be understood that each block of the flowchart diagrams and combinations of the flowchart diagrams may be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, such that the instructions performed by the processor of the computer or other programmable data processing equipment are not described in the flowchart block(s). It creates a means to perform functions. These computer program instructions may also be stored in a computer-usable or computer-readable memory that may direct a computer or other programmable data processing equipment to implement a function in a particular manner, and thus the computer-usable or computer-readable memory. It is also possible that the instructions stored in the flowchart block(s) produce an article of manufacture containing instruction means for performing the function described in the flowchart block(s). The computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to create a computer or other programmable data processing equipment. It is also possible that instructions for performing the processing equipment provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is also possible for the functions recited in blocks to occur out of order. For example, two blocks shown one after another may in fact be performed substantially simultaneously, or it is possible that the blocks are sometimes performed in the reverse order according to the corresponding function.

At this time, the term '~ unit' used in this embodiment means software or hardware components such as FPGA or ASIC, and '~ unit' performs certain roles. However, '~part' is not limited to software or hardware. '~' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Thus, as an example, '~' denotes components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, components and '~ units' may be implemented to play one or more CPUs in a device or secure multimedia card.

In describing the embodiments of the present disclosure in detail, the radio access network New RAN (NR) and the core network packet core (5G System, or 5G Core Network, or NG Core: Next Generation Core) is the main object, but the main gist of the present disclosure is applicable to other communication systems having a similar technical background with slight modifications within the scope not significantly departing from the scope of the present disclosure, which It will be possible by the judgment of a person having technical knowledge skilled in the technical field of the present disclosure.

In the 5G system, in order to support network automation, a network data collection and analysis function (NWDAF), which is a network function that provides a function to analyze and provide data collected from a 5G network, may be defined. NWDAF can collect/store/analyze information from the 5G network and provide the results to unspecified network functions (Network Functions, NFs), and the analysis results can be used independently by each NF.

For convenience of description below, some terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP) standard (standards of 5G, NR, LTE, or similar systems) may be used. However, it is not limited by the terms and names of the present disclosure, and the same may be applied to systems conforming to other standards.

Hereinafter, the present disclosure relates to an apparatus and method for processing a sidelink operation in a discontinuous reception mode (DRX) of a terminal of a wireless communication system. Specifically, the present disclosure is to provide a method of processing sidelink data transmission resource allocation information when the terminal is in the discontinuous reception mode, and sidelink mode 1 in which resources necessary for initial transmission and retransmission of sidelink data are allocated from the base station This can be applied when operating. During the activation time of the discontinuous reception mode, the terminal may monitor the base station's sidelink data initial transmission or retransmission resource allocation control signal. When it is determined that the terminal does not need to monitor the initial transmission or retransmission resource allocation control signal of the base station in the discontinuous reception mode, for example, when receiving a resource allocation control signal instructing new transmission of sidelink data from the base station, The UE may start the DRX deactivation timer. The method of the present disclosure may be applied when sidelink mode 1 in which the terminal is allocated resources required for initial transmission and retransmission of sidelink data from the base station when the terminal operates a bandwidth part (BWP) deactivation timer. When the terminal determines that it has received an initial sidelink data transmission or retransmission resource allocation control signal from the base station in the activation BWP, the terminal may start a BWP deactivation timer corresponding to the activation BWP.

According to an embodiment of the present disclosure, since the terminal does not need to monitor downlink signaling that unnecessarily indicates a sidelink transmission resource in the discontinuous reception mode or the inactive BWP, power consumption of the terminal can be reduced.

Terms that refer to signals, terms that refer to channels, terms that refer to control information, terms that refer to network entities, and terms that refer to components of devices used in the following description are for convenience of description. it is exemplified Therefore, it is not limited to the terms used in the present disclosure, and other terms referring to objects having equivalent technical meanings may be used.

In the following description, a physical channel and a signal may be used interchangeably with data or a control signal. For example, a physical downlink shared channel (PDSCH) is a term referring to a physical channel through which data is transmitted, but the PDSCH may also be used to refer to data. That is, in the present disclosure, an expression 'transmitting a physical channel' may be interpreted equivalently to an expression 'transmitting data or a signal through a physical channel'.

Hereinafter, in the present disclosure, higher signaling refers to a signal transmission method in which a base station is transmitted to a terminal using a downlink data channel of a physical layer or from a terminal to a base station using an uplink data channel of a physical layer. Upper signaling may be understood as radio resource control (RRC) signaling or media access control (MAC) control element (CE).

In addition, in the present disclosure, in order to determine whether a specific condition is satisfied or fulfilled, an expression of more than or less than is used, but this is only a description to express an example, and more or less description is excluded. not to do Conditions described as 'more than' may be replaced with 'more than', conditions described as 'less than', and conditions described as 'more than and less than' may be replaced with 'more than and less than'.

In addition, although the present disclosure describes exemplary embodiments using terms used in some communication standards (eg, 3rd Generation Partnership Project (3GPP)), this is only an example for description. Embodiments of the present disclosure may be easily modified and applied in other communication systems.

1 illustrates a wireless communication system according to an embodiment of the present disclosure.

1 illustrates a base station 110 , a terminal 120 , and a terminal 130 as some of nodes using a wireless channel in a wireless communication system. 1 shows only one base station, other base stations identical to or similar to the base station 110 may be further included.

The base station 110 is a network infrastructure that provides wireless access to the terminals 120 and 130 . The base station 110 has coverage defined as a certain geographic area based on a distance capable of transmitting a signal. In addition to the base station (base station), the base station 110 includes an 'access point (AP)', an 'eNodeB (eNodeB)', a '5G node (5th generation node)', a 'next generation nodeB' , gNB)', 'wireless point', 'transmission/reception point (TRP)' or other terms having an equivalent technical meaning.

Each of the terminal 120 and the terminal 130 is a device used by a user, and performs communication with the base station 110 through a wireless channel. The link from the base station 110 to the terminal 120 or the terminal 130 is downlink (DL), and the link from the terminal 120 or the terminal 130 to the base station 110 is uplink (UL). ) is referred to as In addition, the terminal 120 and the terminal 130 may perform communication through a mutual wireless channel. In this case, the link between the terminal 120 and the terminal 130 is referred to as a sidelink, and the sidelink may also be referred to as a PC5 interface. In some cases, at least one of the terminal 120 and the terminal 130 may be operated without the user's involvement. That is, at least one of the terminal 120 and the terminal 130 is a device that performs machine type communication (MTC) and may not be carried by the user. Each of the terminal 120 and the terminal 130 is a 'user equipment (UE)', a 'mobile station', a 'subscriber station', a 'remote terminal other than a terminal. )', 'wireless terminal', or 'user device' or other terms having an equivalent technical meaning.

The base station 110 , the terminal 120 , and the terminal 130 may transmit and receive radio signals in millimeter wave (mmWave) bands (eg, 28 GHz, 30 GHz, 38 GHz, and 60 GHz). In this case, in order to improve the channel gain, the base station 110 , the terminal 120 , and the terminal 130 may perform beamforming. Here, the beamforming may include transmit beamforming and receive beamforming. That is, the base station 110 , the terminal 120 , and the terminal 130 may impart directivity to a transmission signal or a reception signal. To this end, the base station 110 and the terminals 120 and 130 may select the serving beams 112, 113, 121, and 131 through a beam search or beam management procedure. . After the serving beams 112, 113, 121, and 131 are selected, subsequent communication may be performed through a resource having a quasi co-located (QCL) relationship with the resource transmitting the serving beams 112, 113, 121, 131. Can be performed. have.

If the large-scale characteristics of the channel carrying the symbol on the first antenna port can be inferred from the channel carrying the symbol on the second antenna port, then the first antenna port and the second antenna port are said to be in a QCL relationship. can be evaluated. For example, a wide range of characteristics include delay spread, Doppler spread, Doppler shift, average gain, average delay, spatial receiver parameter. may include at least one of

The terminal 120 and the terminal 120 shown in FIG. 1 may support vehicle communication. In the case of vehicle communication, standardization work for V2X technology based on device-to-device (D2D) communication structure in LTE system has been completed in 3GPP Release 14 and Release 15, and V2X technology based on current 5G NR Efforts to develop are underway. In NR V2X, it is planned to support unicast communication, groupcast (or multicast) communication, and broadcast communication between the UE and the UE. In addition, NR V2X is different from LTE V2X, which aims to transmit and receive basic safety information necessary for vehicle road driving. We aim to provide more advanced services together.

V2X service can be divided into basic safety service and advanced service. Basic safety services include vehicle notification (cooperative awareness messages) or BSM (basic safety message) service, left turn notification service, forward collision warning service, emergency vehicle approach notification service, forward obstacle warning service, and intersection signal information. It may include detailed services such as services, and V2X information may be transmitted/received using a broadcast, unicast, or groupcast transmission method. The advanced service not only has reinforced QoS (quality of service) requirements than the basic safety service, but also unicast in addition to broadcast so that V2X information can be transmitted and received within a specific vehicle group or V2X information can be transmitted and received between two vehicles. and a method capable of transmitting and receiving V2X information using a groupcast transmission method. The advanced service may include detailed services such as platooning service, autonomous driving service, remote driving service, and extended sensor-based V2X service.

Hereinafter, a sidelink (SL) refers to a signal transmission/reception path between a terminal and a terminal, which may be mixed with a PC5 interface. Hereinafter, a base station is a subject that performs resource allocation of a terminal, and may be a base station supporting both V2X communication and general cellular communication, or a base station supporting only V2X communication. That is, the base station may mean an NR base station (eg, gNB), an LTE base station (eg, eNB), or a road site unit (RSU). A terminal is a vehicle supporting vehicle-to-vehicular (V2V) communication (vehicular-to-pedestrian, V2P) as well as general user equipment and mobile station. ) supporting vehicle or pedestrian handset (e.g. smartphone), vehicle-to-network (V2N) communication (vehicular-to-infrastructure) , V2I) may include an RSU equipped with a vehicle and terminal function, an RSU equipped with a base station function, or an RSU equipped with a part of a base station function and a part of a terminal function. In addition, the V2X terminal used in the following description may be referred to as a terminal. That is, in relation to V2X communication, the terminal may be used as a V2X terminal.

The base station and the terminal are connected through the Uu interface. Uplink (UL) refers to a radio link through which the terminal transmits data or control signals to the base station, and downlink (DL) refers to a radio link through which the base station transmits data or control signals to the user equipment.

2 illustrates a configuration of a base station in a wireless communication system according to an embodiment of the present disclosure. The configuration shown in FIG. 2 may be understood as a configuration of the base station 110 . Terms such as '... unit' and '... group' used below mean a unit that processes at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software. have.

Referring to FIG. 2 , the base station 110 includes a wireless communication unit 210 , a backhaul communication unit 220 , a storage unit 230 , and a control unit 240 .

The wireless communication unit 210 performs functions for transmitting and receiving signals through a wireless channel. For example, the wireless communication unit 210 performs a function of converting between a baseband signal and a bit stream according to a physical layer standard of the system. For example, when transmitting data, the wireless communication unit 210 generates complex symbols by encoding and modulating the transmitted bit stream. In addition, when receiving data, the wireless communication unit 210 restores the received bit stream by demodulating and decoding the baseband signal.

In addition, the wireless communication unit 210 up-converts the baseband signal into a radio frequency (RF) band signal, transmits it through the antenna, and downconverts the RF band signal received through the antenna into a baseband signal. To this end, the wireless communication unit 210 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital to analog converter (DAC), an analog to digital converter (ADC), and the like. Also, the wireless communication unit 210 may include a plurality of transmission/reception paths. Furthermore, the wireless communication unit 210 may include at least one antenna array composed of a plurality of antenna elements.

In terms of hardware, the wireless communication unit 210 may be composed of a digital unit and an analog unit, and the analog unit includes a plurality of sub-units according to operating power, operating frequency, and the like. can be composed of The digital unit may be implemented by at least one processor (eg, a digital signal processor (DSP)).

The wireless communication unit 210 transmits and receives signals as described above. Accordingly, all or part of the wireless communication unit 210 may be referred to as a 'transmitter', 'receiver', or 'transceiver'. In addition, in the following description, transmission and reception performed through a wireless channel are used in the meaning of including processing as described above by the wireless communication unit 210 .

The backhaul communication unit 220 provides an interface for communicating with other nodes in the network. That is, the backhaul communication unit 220 converts a bit string transmitted from the base station 110 to another node, for example, another access node, another base station, an upper node, a core network, etc. into a physical signal, and is received from another node. Converts a physical signal into a bit string.

The storage unit 230 stores data such as a basic program, an application program, and setting information for the operation of the base station 110 . The storage unit 230 may be configured as a volatile memory, a non-volatile memory, or a combination of a volatile memory and a non-volatile memory. In addition, the storage unit 230 provides the stored data according to the request of the control unit 240 .

The controller 240 controls overall operations of the base station 110 . For example, the control unit 240 transmits and receives a signal through the wireless communication unit 210 or through the backhaul communication unit 220 . In addition, the control unit 240 writes and reads data in the storage unit 230 . In addition, the control unit 240 may perform functions of a protocol stack required by the communication standard. According to another implementation example, the protocol stack may be included in the wireless communication unit 210 . To this end, the controller 240 may include at least one processor. According to embodiments, the controller 240 may control the base station 110 to perform operations according to embodiments to be described later.

3 illustrates a configuration of a terminal in a wireless communication system according to an embodiment of the present disclosure.

The configuration shown in FIG. 3 may be understood as a configuration of the terminal 120 . Terms such as '... unit' and '... group' used below mean a unit that processes at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software. have.

Referring to FIG. 3 , the terminal 120 includes a communication unit 310 , a storage unit 320 , and a control unit 330 .

The communication unit 310 performs functions for transmitting and receiving signals through a wireless channel. For example, the communication unit 310 performs a function of converting between a baseband signal and a bit stream according to a physical layer standard of the system. For example, when transmitting data, the communication unit 310 generates complex symbols by encoding and modulating the transmitted bit stream. Also, when receiving data, the communication unit 310 restores the received bit stream by demodulating and decoding the baseband signal. In addition, the communication unit 310 up-converts the baseband signal into an RF band signal, transmits the signal through the antenna, and downconverts the RF band signal received through the antenna into a baseband signal. For example, the communication unit 310 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like.

Also, the communication unit 310 may include a plurality of transmission/reception paths. Furthermore, the communication unit 310 may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the communication unit 310 may include a digital circuit and an analog circuit (eg, a radio frequency integrated circuit (RFIC)). Here, the digital circuit and the analog circuit may be implemented as one package. Also, the communication unit 310 may include a plurality of RF chains. Furthermore, the communication unit 310 may perform beamforming.

The communication unit 310 transmits and receives signals as described above. Accordingly, all or part of the communication unit 310 may be referred to as a 'transmitter', 'receiver', or 'transceiver'. In addition, in the following description, transmission and reception performed through a wireless channel are used in the meaning of including processing as described above by the communication unit 310 .

The storage unit 320 stores data such as a basic program, an application program, and setting information for the operation of the terminal 120 . The storage unit 320 may be configured as a volatile memory, a non-volatile memory, or a combination of a volatile memory and a non-volatile memory. In addition, the storage unit 320 provides the stored data according to the request of the control unit 330 .

The controller 330 controls overall operations of the terminal 120 . For example, the control unit 330 transmits and receives signals through the communication unit 310 . In addition, the control unit 330 writes and reads data in the storage unit 320 . In addition, the control unit 330 may perform the functions of the protocol stack required by the communication standard. To this end, the controller 330 may include at least one processor or microprocessor, or may be a part of the processor. Also, a part of the communication unit 310 and the control unit 330 may be referred to as a communication processor (CP). According to some embodiments, the controller 330 may control the terminal 120 to perform operations according to embodiments to be described later.

4 illustrates a configuration of a communication unit in a wireless communication system according to an embodiment of the present disclosure.

4 shows an example of a detailed configuration of the wireless communication unit 210 of FIG. 2 or the communication unit 310 of FIG. 3 . Specifically, FIG. 4 shows components for performing beamforming as a part of the wireless communication unit 210 of FIG. 2 or the communication unit 310 of FIG. 3 .

Referring to FIG. 4 , the wireless communication unit 210 or the communication unit 310 includes an encoding and modulation unit 402 , a digital beamforming unit 404 , a plurality of transmission paths 406-1 to 406-N, and an analog beam. and a forming unit 408 .

The encoding and modulation unit 402 performs channel encoding. For channel encoding, at least one of a low density parity check (LDPC) code, a convolution code, and a polar code may be used. The encoder and modulator 402 generates modulation symbols by performing constellation mapping.

The digital beamformer 404 performs beamforming on a digital signal (eg, modulation symbols). To this end, the digital beamformer 404 multiplies the modulation symbols by beamforming weights. Here, the beamforming weights are used to change the magnitude and phase of a signal, and may be referred to as a 'precoding matrix', a 'precoder', or the like. The digital beamformer 404 outputs digital beamformed modulation symbols to the plurality of transmission paths 406-1 to 406-N. In this case, according to a multiple input multiple output (MIMO) transmission technique, modulation symbols may be multiplexed or the same modulation symbols may be provided to a plurality of transmission paths 406-1 to 406-N.

The plurality of transmission paths 406 - 1 to 406 -N convert digital beamformed digital signals into analog signals. To this end, each of the plurality of transmission paths 406-1 to 406-N may include an inverse fast fourier transform (IFFT) operation unit, a cyclic prefix (CP) insertion unit, a DAC, and an up-converter. The CP insertion unit is for an orthogonal frequency division multiplexing (OFDM) scheme, and may be excluded when another physical layer scheme (eg, filter bank multi-carrier (FBMC)) is applied. That is, the plurality of transmission paths 406 - 1 to 406 -N provide independent signal processing processes for a plurality of streams generated through digital beamforming. However, depending on the implementation method, some of the components of the plurality of transmission paths 406 - 1 to 406 -N may be used in common.

The analog beamformer 408 performs beamforming on an analog signal. To this end, the digital beamforming unit 404 multiplies the analog signals by beamforming weights. Here, the beamforming weights are used to change the magnitude and phase of the signal. Specifically, the analog beamformer 408 may be variously configured according to a connection structure between the plurality of transmission paths 406 - 1 to 406 -N and antennas. For example, each of the plurality of transmission paths 406 - 1 to 406 -N may be connected to one antenna array. As another example, a plurality of transmission paths 406 - 1 to 406 -N may be connected to one antenna array. As another example, the plurality of transmission paths 406 - 1 to 406 -N may be adaptively connected to one antenna array or connected to two or more antenna arrays.

5 illustrates a structure of a radio time-frequency resource of a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 5 , in the radio resource domain, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM symbol (OFDM symbol) or a DFT-S-OFDM symbol (DFT-S-OFDM symbol), and N _symb OFDM symbols or DFT-S-OFDM symbols 530 are one is included in the slot 505 of Unlike the slot, the length of the subframe in the NR system may be defined as 1.0 ms, and the length of the radio frame 500 may be defined as 10 ms. The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth may include a total of N _BW subcarriers 525 . Specific numerical values such as N _symb and N _BW may be variably applied depending on the system.

The basic unit of the time-frequency resource region is a resource element (RE) 510, which may be represented by an OFDM symbol index or a DFT-S-OFDM symbol index and a subcarrier index. A resource block (RB 515) _{may be defined as N RB} consecutive subcarriers 520 in the frequency domain. In general, the minimum data transmission unit is an RB unit, and in an NR system, generally N _symb = 14, N _RB = 12.

The structure of the radio time-frequency resource as shown in FIG. 5 is applied to the Uu interface. In addition, the radio time-frequency resource as shown in FIG. 5 may be similarly applied to the sidelink.

6A illustrates an example of a scenario for sidelink communication according to an embodiment of the present disclosure.

6A illustrates an in-coverage scenario in which the sidelink terminals 620a and 620b are located within the coverage of the base station 610 . The sidelink terminals 620a and 620b receive data and control information from the base station 610 through downlink (DL), or transmit data and control information to the base station through uplink (UL). can In this case, the data and control information may be data and control information for sidelink communication or data and control information for general cellular communication other than sidelink communication. In addition, in FIG. 6A , the sidelink terminals 620a and 620b may transmit/receive data and control information for sidelink communication through the sidelink.

6B illustrates an example of a scenario for sidelink communication according to an embodiment of the present disclosure.

Referring to FIG. 6B , among the sidelink terminals, a first terminal 620a is located within the coverage of a base station 610 and a second terminal 620b is located outside the coverage of the base station 610. In the case of partial coverage is illustrated in Figure 6b. The first terminal 620a located within the coverage of the base station 610 may receive data and control information from the base station through downlink or transmit data and control information to the base station through uplink. The second terminal 620b located outside the coverage of the base station 610 cannot receive data and control information from the base station through downlink, and cannot transmit data and control information to the base station through uplink. The second terminal 620b may transmit and receive data and control information for sidelink communication with the first terminal 620a through the sidelink.

6C illustrates an example of a scenario for sidelink communication according to an embodiment of the present disclosure.

Referring to FIG. 6C , a case in which sidelink terminals (eg, a first terminal 620a and a second terminal 620b) are located outside the coverage of the base station is shown. Accordingly, the first terminal 620a and the second terminal 620b cannot receive data and control information from the base station through downlink, and cannot transmit data and control information through uplink to the base station. The first terminal 620a and the second terminal 620b may transmit and receive data and control information for sidelink communication through the sidelink.

6D illustrates an example of a scenario for sidelink communication according to an embodiment of the present disclosure.

Referring to FIG. 6D , a first terminal 620a and a second terminal 620b performing sidelink communication are connected to different base stations (eg, a first base station 610a and a second base station 610b). (eg, RRC connected state) or camping state (eg, RRC disconnected state, that is, RRC idle state) may perform inter-cell sidelink communication. In this case, the first terminal 620a may be a sidelink transmitting terminal and the second terminal 620b may be a sidelink receiving terminal. Alternatively, the first terminal 620a may be a sidelink receiving terminal and the second terminal 620b may be a sidelink transmitting terminal. The first terminal 620a may receive a sidelink dedicated system information block (SIB) from the base station 610a to which it is connected (or to which it is camping), and the second terminal 620b is connected to the second terminal 620b. It may receive a sidelink dedicated SIB from another base station 620b (or it is camping). In this case, the information on the sidelink dedicated SIB received by the first terminal 620a and the information on the sidelink dedicated SIB received by the second terminal 620b may be different from each other. Accordingly, information needs to be unified in order to perform sidelink communication between terminals located in different cells.

In the above-described examples of FIGS. 6A to 6D, for convenience of explanation, a sidelink system composed of two terminals (eg, the first terminal 610a and the second terminal 620b) has been described as an example, but the present disclosure is not limited thereto, and may be applied to a sidelink system in which two or more terminals participate. In addition, the uplink and downlink between the base stations 610, 610a, and 610b and the sidelink terminals 620a and 620b may be referred to as a Uu interface, and the sidelink between the sidelink terminals is referred to as a PC-5 interface. can be In the following description, uplink or downlink and Uu interface, sidelink and PC-5 may be used interchangeably.

Meanwhile, in the present disclosure, the terminal supports vehicle-to-vehicle communication (vehicular-to-vehicular, V2V), vehicle-to-pedestrian communication (vehicular-to-pedestrian, V2P) supporting vehicle or pedestrian handset (eg: smartphone), a vehicle supporting vehicle-to-network communication (vehicular-to-network, V2N), or a vehicle supporting vehicle-to-infrastructure communication (vehicular-to-infrastructure, V2I). . Also, in the present disclosure, a terminal may mean a road side unit (RSU) equipped with a terminal function, an RSU equipped with a base station function, or an RSU equipped with a part of a base station function and a part of a terminal function.

7A and 7B are diagrams for explaining a transmission method of sidelink communication according to an embodiment of the present disclosure.

Specifically, FIG. 7A shows a unicast scheme, and FIG. 7B shows a groupcast scheme.

Referring to FIG. 7A , a transmitting terminal 720a and a receiving terminal 720b may perform one-to-one communication. The transmission method as shown in FIG. 7A may be referred to as unicast communication. Referring to FIG. 7B , the transmitting terminal 720a or 720d and the receiving terminals 720b , 720c , 720e , 720f and 720g may perform one-to-many communication. The transmission method shown in FIG. 7B may be referred to as a groupcast or multicast. In FIG. 7B , a first terminal 720a , a second terminal 720b , and a third terminal 720c form one group, perform groupcast communication, and a fourth terminal 720d and a fourth terminal 720d The fifth terminal 720e, the sixth terminal 720f, and the seventh terminal 720g may form another group and perform groupcast communication. The terminals may perform groupcast communication within a group to which they belong, and may perform unicast, groupcast, or broadcast communication with at least one other terminal belonging to different groups. Although two groups are illustrated in FIG. 7B for convenience of explanation, the present disclosure is not limited thereto, and may be applied even when a larger number of groups is formed.

Meanwhile, although not shown in FIG. 7A or FIG. 7B , the sidelink terminals may perform broadcast communication. Broadcast communication refers to a method in which all sidelink terminals receive data and control information transmitted by the sidelink transmitting terminal through the sidelink. For example, in FIG. 7B , if the first terminal 720a is a transmitting terminal, the remaining terminals 720b, 720c, 720d, 720e, 720f, and 720g receive data and control information transmitted by the first terminal 720a. can do.

The aforementioned sidelink unicast communication, groupcast communication, and broadcast communication are supported in an in-coverage scenario, a partial-coverage scenario, or an out-of-coverage scenario. can be

In the case of NR sidelink, unlike in LTE sidelink, a transmission type in which a vehicle terminal transmits data to only one specific terminal through unicast and a transmission type in which data is transmitted to a plurality of specific terminals through groupcast support This can be considered. For example, when considering a service scenario such as platooning, which is a technology that connects two or more vehicles in a single network and moves in a cluster form, these unicast and groupcast technologies may be usefully used. Specifically, a leader terminal of a group connected by platooning may use unicast communication for the purpose of controlling one specific terminal, and groupcast communication for the purpose of simultaneously controlling a group consisting of a plurality of specific terminals this can be used

The following method may be used for resource allocation in the V2X system.

(1) Mode 1 resource allocation

Scheduled resource allocation is a method in which a base station allocates resources used for sidelink transmission to RRC-connected terminals in a dedicated scheduling method. The scheduled resource allocation method may be effective for interference management and resource pool management (dynamic allocation and/or semi-persistent transmission) since the base station can manage sidelink resources. When there is data to be transmitted to other terminal(s), the RRC connected mode terminal transmits information notifying that there is data to be transmitted to other terminal(s) using an RRC message or a MAC control element (hereinafter 'CE') to the base station. can be sent to For example, the RRC message transmitted by the terminal to the base station may be a sidelink terminal information (SidelinkUEInformation), a terminal assistance information (UEAssistanceInformation) message, and the MAC CE is a buffer status report (BSR) for V2X communication. BSR MAC CE, SR (scheduling request), etc. which include at least one of an indicator indicating that , and information on the size of data buffered for sidelink communication may correspond.

(2) Mode 2 resource allocation

Second, UE autonomous resource selection is provided to the terminal as sidelink transmission/reception resource pooling system information or RRC message (eg RRCReconfiguration message, PC5-RRC message) for V2X, and the terminal This is a method of selecting a resource pool and resources according to this set rule. The terminal autonomous resource selection may correspond to one or a plurality of methods of allocating resources below.

> The UE autonomously selects a sidelink resource for transmission (UE autonomously selects sidelink resource for transmission).

> The UE assists sidelink resource selection for other UEs (UE assists sidelink resource selection for other UEs).

> The terminal receives a configured grant of NR for sidelink transmission (UE is configured with NR configured grant for sidelink transmission).

> The UE may schedule sidelink transmission of other UEs (UE schedules sidelink transmission of other UEs).

- The resource selection method of the UE may include zone mapping, sensing-based resource selection, random selection, and the like.

- In addition, even if the terminal exists in the coverage of the base station, resource allocation or resource selection may not be performed in the scheduled resource allocation or terminal autonomous resource selection mode. pool) may perform V2X sidelink communication.

- In addition, when terminals for V2X communication exist outside the coverage of the base station, the terminal may perform V2X sidelink communication through a preset sidelink transmission/reception resource pool.

8 is a diagram illustrating an operation in which a terminal processes sidelink resource allocation information in a discontinuous reception mode according to an embodiment of the present disclosure.

Referring to FIG. 8 , when the discontinuous reception mode is configured and the sidelink mode 1 resource allocation is configured for the UE in the RRC connection state, in step 800, the UE may determine whether the activation time is in operation.

In step 802, the terminal may monitor the downlink control signaling of the base station and may determine whether a sidelink transmission resource is allocated. For example, the downlink control signaling of the base station may include a physical downlink control channel (PDCCH). In downlink control signaling, the sidelink resource allocation indication may be determined using a sidelink identifier of the terminal, for example, sidelink RNTI (SL-RNTI) or sidelink configured scheduling RNTI (SL-CS-RNTI). That is, the UE may monitor the PDCCH and may detect reception of an SL grant indicating a sidelink resource allocation indication.

In step 804, the UE may determine whether the allocated sidelink transmission resource indicated in the downlink control signaling is for a new transmission. That is, the UE may determine whether the sidelink resource allocation indication indicated in the PDCCH is for new transmission. Thereafter, the UE may newly transmit or retransmit the sidelink MAC PDU using the allocated resource in step 804 . In an embodiment, when it is determined that the sidelink transmission resource is for new transmission, in step 806, the UE may start (or restart) the DRX deactivation timer. If it is determined in step 804 that the sidelink transmission resource is for retransmission purposes according to the determination in step 804, in step 808, the UE may determine whether a HARQ process in which sidelink HARQ feedback (SL HARQ (hybrid automatic repeat request) feedback) is configured. That is, the terminal may determine whether the sidelink HARQ feedback is activated. If the drx-RetransmissionTimerSL is not running, the UE may perform step 808 without performing step 818 even if it is determined that the sidelink transmission resource is for retransmission. Alternatively, the UE may stop drx-RetransmissionTimerSL in step 818 when it is determined that the sidelink transmission resource is for retransmission when drx-RetransmissionTimerSL is running.

In an embodiment, when the sidelink HARQ feedback is a configured HARQ process, the transmitting terminal may determine whether to retransmit based on the HARQ feedback from the receiving terminal. Then, the terminal may proceed to step 810 . In this case, the terminal may obtain HARQ feedback from the receiving terminal in step 810 . HARQ feedback may be used for indicating ACK or NAK. Alternatively, the HARQ feedback may be used for the purpose of indicating the NAK. That is, in step 810, the UE may receive HARQ feedback for sidelink MAC PDU (SL MAC PDU) transmission.

In step 812, the UE may report the HARQ feedback of step 810 to the base station. According to an embodiment, the base station may be referred to as a network (NW).

In step 814, the UE may start drx-HARQ-RTT (Round Trip Time)-TimerSL. Here, drx-HARQ-RTT-TimerSL may mean the minimum time required for the base station to process the HARQ feedback report received from the terminal (the minimum duration before a SL grant for HARQ retransmission is expected by the MAC entity). . The drx-HARQ-RTT_TimerSL may operate for each sidelink HARQ process.

In step 816, the UE may end drx-HARQ-RTT-TimerSL.

In step 822, the terminal may determine whether retransmission is necessary. For example, when the terminal determines that the HARQ feedback obtained from the receiving terminal indicates the NAK and it is necessary to retransmit the sidelink MAC PDU to the receiving terminal, the terminal may determine that retransmission is necessary. And, when it is determined that the terminal needs to retransmit the sidelink MAC PDU to the receiving terminal, in step 820, the terminal can start drx-RetransmissionTimerSL to wait for an SL grant allocated for retransmission of the sidelink MAC PDU from the base station. . Then, the UE may proceed to steps 800 and 802 and wait for an SL grant for sidelink MAC PDU retransmission from the base station.

Alternatively, if it is determined in step 822 that the terminal does not need to retransmit the sidelink MAC PDU to the receiving terminal, the terminal may end the operation.

In step 818, if it is determined that the SL grant for sidelink MAC PDU retransmission is obtained from the base station, the terminal may stop drx-RetransmissionTimerSL.

In one embodiment, when it is determined that the sidelink HARQ feedback is not configured as a HARQ process according to the determination in step 808, that is, when the sidelink HARQ feedback is deactivated, the terminal configures retransmission without HARQ feedback from the receiving terminal Whether to retransmit may be determined based on the value. The UE may start drx-RetransmissionTimerSL to wait for an SL grant allocated for sidelink MAC PDU retransmission from the base station. In this case, the terminal proceeds to steps 800 and 802 to monitor whether resource allocation is indicated for new transmission or retransmission. For example, the UE may monitor the PDCCH in step 802 and detect reception of an SL grant indicating a sidelink resource allocation indication. The UE may stop drx-RetransmissionTimerSL when it is determined that the SL grant for sidelink MAC PDU retransmission is received.

When the discontinuous reception mode is set in the terminal performing sidelink-based data transmission/reception according to an embodiment of the present disclosure, the active time may include the following. That is, when the discontinuous reception mode is set, the UE may monitor the PDCCH at the activation time. Examples included in the activation time for monitoring the PDCCH are as follows. Here, drx-RetransmissionTimerSL and Scheduling request for SL-SCH may be used when sidelink mode 1 resource allocation is configured.

- drx-onDurationTimer or drx-InactivityTimer or drx-RetransmissionTimerDL or drx-RetransmissionTimerUL or ra-ContentionResolutionTimer or drx-RetransmissionTimerSL is running; or

- a Scheduling Request is sent on PUCCH and is pending (ie, a Scheduling Request is triggered and not cancelled) sent and pending (ie, a scheduling request has been triggered and not canceled); or

- a PDCCH indicating a new transmission addressed to the C-RNTI of the MAC entity has not been received after successful reception of a Random Access Response for the Random Access Preamble not selected by the MAC entity among the contention-based Random Access Preamble After successful reception of a random access response to a random access preamble not selected by the MAC entity among the random access preambles, wait for a PDCCH indicating a new transmission addressed to the C-RNTI of the MAC entity).

In an embodiment, drx-RetransmissionTimerSL may mean a maximum time until obtaining an allocated resource for sidelink transmission (the maximum duration until a grant for sidelink transmission is received). The drx-RetransmissionTimerSL may be operated for each sidelink HARQ process. drx-RetransmissionTimerSL may be operated when sidelink MAC PDU retransmission is required.

Configuration information required for the terminal to operate the sidelink mode 1 resource allocation in the discontinuous reception mode according to an embodiment of the present disclosure is delivered through dedicated RRC signaling, for example, an RRCReconfiguration message or an RRCConnectionReconfiguration message transmitted by the base station to the terminal can be An example of the configuration information required for the above-described terminal to operate the sidelink mode 1 resource allocation in the discontinuous reception mode is shown in Table 1 below.

9 is a diagram illustrating an operation in which a terminal processes sidelink resource allocation information in a discontinuous reception mode according to an embodiment of the present disclosure.

Referring to FIG. 9 , in step 900, the UE may determine that the discontinuous reception mode of the RRC connection state is set.

In step 902, the terminal may determine that the sidelink mode 1 resource allocation is set.

In step 904, the terminal may monitor the downlink control signaling (eg, PDCCH) of the base station, and may determine whether a sidelink transmission resource is allocated. Thereafter, the terminal may newly transmit or retransmit the sidelink MAC PDU by using the allocated sidelink transmission resource in step 904 . That is, the UE may monitor the PDCCH in step 904 and detect reception of an SL grant indicating a sidelink resource allocation indication.

In step 906, the UE may determine whether the sidelink HARQ feedback is a configured HARQ process. That is, the terminal may determine whether the sidelink HARQ feedback is activated.

In an embodiment, when the sidelink HARQ feedback is a configured HARQ process, the transmitting terminal may determine whether to retransmit based on the HARQ feedback from the receiving terminal. And the terminal may proceed to step 908. In this case, the terminal may obtain HARQ feedback from the receiving terminal in step 908 . HARQ feedback may be used for indicating ACK or NAK. Alternatively, the HARQ feedback may be used for the purpose of indicating the NAK. That is, in step 908, the UE may receive HARQ feedback for sidelink MAC PDU (SL MAC PDU) transmission.

In step 910, the terminal may report the obtained HARQ feedback to the base station.

In step 912, the UE may start drx-HARQ-RTT-TimerSL. Here, drx-HARQ-RTT-TimerSL may mean the minimum time required for the base station to process the HARQ feedback report received from the terminal (the minimum duration before a SL grant for HARQ retransmission is expected by the MAC entity). The drx-HARQ-RTT_TimerSL may operate for each sidelink HARQ process.

In step 914, the UE may stop drx-HARQ_RTT-TimerSL.

In one embodiment, when it is determined that the sidelink HARQ feedback is not configured as a HARQ process according to the determination in step 906, that is, when the sidelink HARQ feedback is deactivated, the terminal configures retransmission without HARQ feedback from the receiving terminal Whether to retransmit or not may be determined based on the value. In this case, the UE may monitor whether resource allocation is indicated for new transmission or retransmission in step 904 . For example, the UE may monitor the PDCCH in step 904 and detect reception of an SL grant indicating a sidelink resource allocation indication. When the UE determines that sidelink MAC PDU retransmission is necessary (eg, determines whether sidelink MAC PDU retransmission is necessary based on the maximum HARQ retransmission number set for the corresponding HARQ process), the UE determines that the base station retransmits the sidelink MAC PDU Start drx-RetransmissionTimerSL to wait for PDCCH for SL grant indicating resource, and if PDCCH indicating allocation of sidelink MAC PDU retransmission resource for the HARQ process is obtained, drx-RetransmissionTimerSL can be stopped. 8 and 9, the terminal processing drx-RetranmissionTimerSL and drx-HARQ-RTT-TimerSL in consideration of all cases in which the HARQ feedback report reported by the terminal to the base station includes acknowledgment or non-acknowledgement. explain the operation of According to an embodiment, non-acknowledgement may be referred to as NAK or NACK.

According to an embodiment of the present disclosure, only when the HARQ feedback report reported by the terminal to the base station includes non-acknowledgement, drx-RetranmissionTimerSL and drx-HARQ-RTT-TimerSL For an operation embodiment of the terminal, It will be described with reference to FIG. 10 .

10 is a diagram illustrating an operation in which a terminal processes sidelink resource allocation information in a discontinuous reception mode according to an embodiment of the present disclosure.

Referring to FIG. 10, if the sidelink mode 1 resource allocation is set and the discontinuous reception mode is set for the terminal, the terminal determines in step 1000 that HARQ feedback for the sidelink MAC PDU to be transmitted to the receiving terminal has been obtained. can That is, the UE may receive HARQ feedback for sidelink MAC PDU transmission. The operation of step 1000 may be performed for a HARQ process in which feedback-based HARQ is configured and a sidelink MAC PDU corresponding to the HARQ process.

In step 1002, the terminal may transmit a HARQ feedback report to the base station. That is, the terminal may report the HARQ feedback of step 1000 to the base station. In one embodiment, the HARQ feedback report may be referred to as a HARQ report or HARQ feedback.

In step 1004, the UE may determine whether the HARQ feedback report indicates non-acknowledgement for the sidelink MAC PDU. If the HARQ feedback report indicates non-acknowledgement for the sidelink MAC PDU, the UE may start drx-HARQ-RTT-TimerSL in step 1006 . Here, drx-HARQ-RTT-TimerSL may mean the minimum time required for the base station to process the HARQ feedback report received from the terminal (the minimum duration before a SL grant for HARQ retransmission is expected by the MAC entity). According to an embodiment, drx-HARQ-RTT_TimerSL may operate for each sidelink HARQ process.

In step 1008, the UE may stop drx-HARQ-RTT-TimerSL.

According to an embodiment, in step 1004, when the UE determines that the HARQ feedback report does not indicate non-acknowledgement for the sidelink MAC PDU, that is, the UE indicates that the HARQ feedback report indicates an acknowledgment for the sidelink MAC PDU. If it is determined, the terminal may proceed to step 1010 .

In step 1010, the terminal may perform another procedure. For example, the terminal may perform an operation of transmitting a new MAC PDU. Alternatively, the UE may perform an operation of retransmitting the MAC PDU based on the retransmission setting value for the HARQ process in which the feedback-based HARQ is not configured.

When the UE performs an operation of retransmitting the MAC PDU based on the retransmission setting value for the HARQ process in which the feedback-based HARQ is not configured, the UE determines that sidelink MAC PDU retransmission is necessary (e.g., the corresponding Determining whether sidelink MAC PDU retransmission is necessary based on the maximum HARQ retransmission number set for the HARQ process), the terminal starts drx-RetransmissionTimerSL to wait for the PDCCH for the SL grant indicating the sidelink MAC PDU retransmission resource by the base station and When a PDCCH indicating sidelink MAC PDU retransmission resource allocation for the HARQ process is acquired, drx-RetransmissionTimerSL may be stopped.

11 is a diagram illustrating an operation in which a terminal processes sidelink resource allocation information in a discontinuous reception mode according to an embodiment of the present disclosure.

Referring to FIG. 11 , in step 1100 , the UE may determine whether the drx-HARQ-RTT-TimerSL in operation has ended. That is, the UE may identify whether the drx-HARQ-RTT-TimerSL in operation has expired.

In step 1102, the UE may determine whether the HARQ feedback report indicates non-acknowledgement for the sidelink MAC PDU. That is, the terminal may determine whether the HARQ feedback report for the sidelink MAC PDU transmitted to the base station indicates non-acknowledgement. According to the determination in step 1102, if it is determined that the HARQ feedback report indicates non-acknowledgement, the terminal may start drx-RetransmissionTimerSL in step 1104. Alternatively, according to the determination of step 1102, when the terminal determines that the HARQ feedback report does not indicate non-acknowledgement, that is, when the terminal determines that the HARQ feedback report indicates acknowledgment, the terminal may proceed to step 1106. .

In step 1106, the terminal may perform another procedure. For example, the terminal may perform an operation of transmitting a new MAC PDU. Alternatively, the UE may perform an operation of retransmitting the MAC PDU based on the retransmission setting value for the HARQ process in which the feedback-based HARQ is not configured.

When the UE performs an operation of retransmitting the MAC PDU based on the retransmission setting value for the HARQ process in which the feedback-based HARQ is not configured, the UE determines that sidelink MAC PDU retransmission is necessary (e.g., the corresponding Determining whether sidelink MAC PDU retransmission is necessary based on the maximum HARQ retransmission number set for the HARQ process), the terminal starts drx-RetransmissionTimerSL to wait for the PDCCH for the SL grant indicating the sidelink MAC PDU retransmission resource by the base station and When a PDCCH indicating sidelink MAC PDU retransmission resource allocation for the HARQ process is acquired, drx-RetransmissionTimerSL may be stopped.

According to the embodiments of the present disclosure described with reference to FIGS. 8, 9, 10 and 11 described above with reference to FIGS. 8, 9, 10 and 11, the terminal in which the sidelink mode 1 resource allocation is set in the discontinuous reception mode may perform the procedure of [Table 2]. have.

According to an embodiment of the present disclosure, when the terminal processes the sidelink mode 1 resource allocation configuration in the discontinuous reception mode, the terminal HARQ RTT timer (drx-HARQ-RTT-TimerSL) for the HARQ feedback report transmitted to the base station drx-RetransmissionTimerSL corresponding to a timer waiting for resource allocation for sidelink MAC PDU retransmission from the base station may be operated without operating . Here, drx-RetransmissionTimerSL may be operated only when the UE determines that resource allocation for sidelink MAC PDU retransmission is necessary from the base station.

12A is a diagram illustrating an operation in which a terminal processes sidelink resource allocation information in a discontinuous reception mode according to an embodiment of the present disclosure.

Referring to FIG. 12A , in step 1200, the UE may transmit a HARQ feedback report to the base station. That is, the terminal may report the HARQ report to the base station.

In step 1202, the UE may determine whether the HARQ feedback report indicates non-acknowledgement for the sidelink MAC PDU. According to the determination in step 1202, if it is determined that the HARQ feedback report indicates non-acknowledgement, the UE may start drx-RetranmissionTimerSL in step 1204.

In step 1206, the terminal may determine that the resource for retransmission of the sidelink MAC PDU has been allocated from the base station. That is, the UE may detect an SL grant indication for sidelink MAC PDU retransmission. For example, the UE may detect an SL grant indication for sidelink MAC PDU retransmission by monitoring the PDCCH.

In step 1208, the UE may stop drx-RetransmissionTimerSL.

According to an embodiment, when it is determined that the HARQ feedback report does not indicate non-acknowledgement according to the determination in step 1202, that is, when it is determined that the HARQ feedback report indicates acknowledgment, the terminal may proceed to step 1210.

In step 1210, the terminal may perform another procedure. For example, the terminal may perform an operation of newly transmitting a sidelink MAC PDU. Alternatively, the UE may perform an operation of retransmitting the MAC PDU based on the retransmission setting value for the HARQ process in which the feedback-based HARQ is not configured.

When the UE performs an operation of retransmitting the MAC PDU based on the retransmission setting value for the HARQ process in which the feedback-based HARQ is not configured, the UE determines that sidelink MAC PDU retransmission is necessary (e.g., the corresponding Determining whether sidelink MAC PDU retransmission is necessary based on the maximum HARQ retransmission number set for the HARQ process), the terminal starts drx-RetransmissionTimerSL to wait for the PDCCH for the SL grant indicating the sidelink MAC PDU retransmission resource by the base station and When a PDCCH indicating sidelink MAC PDU retransmission resource allocation for the HARQ process is acquired, drx-RetransmissionTimerSL may be stopped.

12B is a diagram illustrating an operation in which a terminal processes sidelink resource allocation information in a discontinuous reception mode according to an embodiment of the present disclosure.

Referring to FIG. 12B , in step 1250, the terminal may transmit an HARQ feedback report to the base station.

In step 1252, the UE may start drx-RetranmissionTimerSL.

In step 1254, the terminal may determine that the resource for retransmission of the sidelink MAC PDU has been allocated from the base station. That is, the UE may detect an SL grant indication for sidelink MAC PDU retransmission. For example, the UE may detect an SL grant indication for sidelink MAC PDU retransmission by monitoring the PDCCH.

In step 1256, the UE may stop drx-RetransmissionTimerSL.

As described with reference to FIGS. 12A and 12B , a terminal in which the discontinuous reception mode is configured and the sidelink mode 1 resource allocation is configured according to embodiments of the present disclosure may perform the procedure of [Table 3].

According to an embodiment of the present disclosure, an operation of processing a sidelink operation in a serving cell in which bwp-InactivityTimer is set when the terminal operates an inactive BWP may be the same as the procedure in [Table 4]. Since the sidelink mode 1 resource allocation is configured for the terminal, the terminal may acquire sidelink resources for new transmission or retransmission of the sidelink MAC PDU from the base station. Downlink control signaling (eg, PDCCH) transmitted from the base station may indicate the sidelink transmission resource allocated to the terminal by the sidelink identifier (SL-RNTI or SL-CS-RNTI) of the terminal.

According to an embodiment of the present disclosure, in a method for a terminal to process sidelink information in a discontinuous reception mode in a wireless communication system, a DRX inactivity timer (drx-InactivityTimer) when the terminal receives resource allocation required for new sidelink transmission Steps of starting , determining whether sidelink retransmission resource allocation should be monitored during the active time, and operating a sidelink retransmission resource allocation standby timer if monitoring of sidelink retransmission resource allocation is required during the activation time and determining sidelink retransmission resource allocation during the activation time.

The present disclosure relates to a method of processing resource allocation for sidelink MAC PDU transmission or retransmission when a sidelink mode 1 resource allocation is configured in a terminal in a discontinuous reception mode in a wireless communication system, the method comprising: determining whether sidelink transmission resource allocation is obtained by monitoring downlink control signaling of the base station during the activation time of transmitting the HARQ feedback report for the sidelink MAC PDU to the base station and determining to operate the report processing timer; and acquiring retransmission resources when the HARQ feedback report for the sidelink MAC PDU indicates acknowledgment It may include the steps of determining not to operate a timer waiting for , and operating a timer waiting for retransmission resource acquisition when the HARQ feedback report for the sidelink MAC PDU indicates non-acknowledgement.

According to an embodiment of the present disclosure, in a method of operating a first terminal in a wireless communication system, the first terminal is in a radio resource control (RRC) connection state, a discontinuous reception (DRX) is set to the first terminal, Monitoring a physical downlink control channel (PDCCH) transmitted from a base station in an active time related to the DRX when the sidelink resource allocation mode 1 is configured for the first terminal, based on the monitoring of the PDCCH , detecting information related to a sidelink resource allocated by the base station, identifying whether the sidelink resource is a resource for new transmission of a sidelink signal or a resource for retransmission of the sidelink signal; When the sidelink resource is a resource for retransmission of the sidelink signal, identifying whether sidelink HARQ feedback is activated for a sidelink hybrid automatic repeat request (HARQ) process of the first terminal, the side When link HARQ feedback is activated, receiving sidelink HARQ feedback information for a sidelink signal transmitted from the first terminal to a second terminal from a second terminal, and receiving the received sidelink HARQ feedback information from the base station and, in response to the report, starting a sidelink HARQ round trip time (RTT) timer related to the DRX.

According to an embodiment, the operating method of the first terminal may further include starting an inactivity timer related to the DRX when the sidelink resource is a resource for new transmission of the sidelink signal. can

According to an embodiment, the operating method of the first terminal identifies whether the sidelink signal is retransmitted based on a preset value related to the retransmission of the sidelink signal when the sidelink HARQ feedback is not activated. and starting a sidelink retransmission timer associated with the DRX when it is identified that retransmission of the sidelink signal is required.

According to an embodiment, the DRX-related sidelink retransmission timer indicates a maximum time until the first terminal acquires the resource allocated for retransmission of the sidelink signal, and the DRX-related sidelink retransmission timer The timer may be driven for each sidelink HARQ process of the terminal.

According to an embodiment, the method of operating the first terminal further includes stopping a sidelink retransmission timer related to the DRX when the first terminal acquires a resource allocated for retransmission of the sidelink signal. can do.

According to an embodiment, the DRX-related sidelink HARQ-RTT timer may indicate the minimum time required for the base station to process the report on the sidelink HARQ feedback information transmitted by the first terminal.

According to an embodiment, the sidelink HARQ-RTT timer related to the DRX may be driven for each sidelink HARQ process of the terminal.

According to an embodiment, the active time related to the DRX may include a period in which a scheduling request for the sidelink is transmitted to the base station over a physical uplink control channel (PUCCH).

According to an embodiment of the present disclosure, in a wireless communication system, a first terminal, a transceiver, and the first terminal are in a radio resource control (RRC) connection state, and discontinuous reception (DRX) is set to the first terminal, and , when sidelink resource allocation mode 1 is configured for the first terminal, monitoring a physical downlink control channel (PDCCH) transmitted from a base station in an active time related to the DRX, and monitoring the PDCCH , detects information related to a sidelink resource allocated by the base station, identifies whether the sidelink resource is a resource for new transmission of a sidelink signal or a resource for retransmission of the sidelink signal, and When the link resource is a resource for retransmission of the sidelink signal, it is identified whether sidelink HARQ feedback is activated for the sidelink hybrid automatic repeat request (HARQ) process of the first terminal, and the sidelink HARQ feedback is activated, the sidelink HARQ feedback information for the sidelink signal transmitted from the first terminal to the second terminal is received from the second terminal through the transceiver, and the received sidelink information is received from the second terminal through the transceiver. and reporting HARQ feedback information to the base station and starting a sidelink HARQ round trip time (RTT) timer related to the DRX in response to the report.

According to an embodiment, when the sidelink resource is a resource for new transmission of the sidelink signal, the at least one processor may start an inactivity timer related to the DRX.

According to an embodiment, when the sidelink HARQ feedback is not activated, the at least one processor identifies whether to retransmit the sidelink signal based on a preset value related to the retransmission of the sidelink signal, and , when it is identified that retransmission of the sidelink signal is necessary, a sidelink retransmission timer related to the DRX may be started.

According to an embodiment, the DRX-related sidelink retransmission timer indicates a maximum time until the first terminal acquires the resource allocated for retransmission of the sidelink signal, and the DRX-related sidelink retransmission timer The timer may be driven for each sidelink HARQ process of the terminal.

According to an embodiment, the at least one processor may stop a sidelink retransmission timer related to the DRX when the first terminal acquires a resource allocated for retransmission of the sidelink signal.

According to an embodiment, the sidelink HARQ-RTT timer related to the DRX indicates a minimum time required for the base station to process the report on the sidelink HARQ feedback information transmitted by the first terminal, and the DRX and The related sidelink HARQ-RTT timer may be driven for each sidelink HARQ process of the terminal.

According to an embodiment, the active time related to the DRX may include a period in which a scheduling request for the sidelink is transmitted to the base station over a physical uplink control channel (PUCCH).

Methods according to the embodiments described in the claims of the present disclosure or the description of the invention may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented in software, a computer-readable storage medium or computer program product storing one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium or computer program product are configured for execution by one or more processors in an electronic device (device). One or more programs include instructions for causing an electronic device to execute methods according to embodiments described in a claim or specification of the present disclosure.

Such programs (software modules, software) include random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable ROM (EEPROM: Electrically Erasable Programmable Read Only Memory), magnetic disc storage device, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or any other form of It may be stored in an optical storage device or a magnetic cassette. Alternatively, it may be stored in a memory composed of a combination of some or all thereof. In addition, each configuration memory may be included in plurality.

In addition, the program accesses through a communication network composed of a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. It may be stored in an attachable storage device that can be accessed. Such a storage device may be connected to a device implementing an embodiment of the present disclosure through an external port. In addition, a separate storage device on the communication network may be connected to the device implementing the embodiment of the present disclosure.

In the present disclosure, the term "computer program product" or "computer readable medium" refers to a medium such as a memory, a hard disk installed in a hard disk drive, and a signal as a whole. used for These "computer program product" or "computer-readable recording medium" are means provided for a method of processing a sidelink operation in a discontinuous reception mode of a terminal of a wireless communication system according to the present disclosure.

In the specific embodiments of the present disclosure described above, elements included in the present disclosure are expressed in the singular or plural according to the specific embodiments presented. However, the singular or plural expression is appropriately selected for the context presented for convenience of description, and the present disclosure is not limited to the singular or plural element, and even if the element is expressed in plural, it is composed of the singular or singular. Even an expressed component may be composed of a plurality of components.

Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, various modifications are possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments and should be defined by the claims described below as well as the claims and equivalents.

Claims (15)

A method of operating a first terminal in a wireless communication system, the method comprising:
When the first terminal is in a radio resource control (RRC) connection state, discontinuous reception (DRX) is configured for the first terminal, and sidelink resource allocation mode 1 is configured for the first terminal, the DRX-related activity monitoring a physical downlink control channel (PDCCH) transmitted from a base station at an active time;
detecting information related to a sidelink resource allocated by the base station based on the monitoring of the PDCCH;
identifying whether the sidelink resource is a resource for new transmission of a sidelink signal or a resource for retransmission of the sidelink signal;
identifying whether sidelink HARQ feedback is activated for a sidelink hybrid automatic repeat request (HARQ) process of the first terminal when the sidelink resource is a resource for retransmission of the sidelink signal;
receiving sidelink HARQ feedback information for a sidelink signal transmitted from the first terminal to a second terminal from a second terminal when the sidelink HARQ feedback is activated;
reporting the received sidelink HARQ feedback information to the base station; and
in response to the report, starting a sidelink HARQ round trip time (RTT) timer associated with the DRX;
How to include.
According to claim 1,
starting an inactivity timer related to the DRX when the sidelink resource is a resource for new transmission of the sidelink signal;
How to include more.
According to claim 1,
when the sidelink HARQ feedback is not activated, identifying whether to retransmit the sidelink signal based on a preset value related to the retransmission of the sidelink signal; and
starting a sidelink retransmission timer associated with the DRX when it is identified that retransmission of the sidelink signal is required;
How to include more.
4. The method of claim 3,
The DRX-related sidelink retransmission timer indicates a maximum time until the first terminal acquires a resource allocated for retransmission of the sidelink signal,
The DRX-related sidelink retransmission timer is driven for each sidelink HARQ process of the terminal.
5. The method of claim 4,
stopping, by the first terminal, a sidelink retransmission timer related to the DRX when the resource allocated for retransmission of the sidelink signal is obtained;
How to include more.
According to claim 1,
The DRX-related sidelink HARQ-RTT timer indicates a minimum time required for the base station to process a report on the sidelink HARQ feedback information transmitted by the first terminal.
According to claim 1,
The DRX-related sidelink HARQ-RTT timer is driven for each sidelink HARQ process of the terminal.
According to claim 1,
The active time associated with the DRX is,
and a period during which the scheduling request for the sidelink is transmitted to the base station on a physical uplink control channel (PUCCH).
In a first terminal in a wireless communication system,
transceiver; and
When the first terminal is in a radio resource control (RRC) connection state, discontinuous reception (DRX) is configured for the first terminal, and sidelink resource allocation mode 1 is configured for the first terminal, the DRX-related activity Monitoring a physical downlink control channel (PDCCH) transmitted from the base station in time (active time),
Based on the monitoring of the PDCCH, detecting information related to a sidelink resource allocated by the base station,
Identifies whether the sidelink resource is a resource for new transmission of a sidelink signal or a resource for retransmission of the sidelink signal,
When the sidelink resource is a resource for retransmission of the sidelink signal, identifying whether sidelink HARQ feedback is activated for a sidelink hybrid automatic repeat request (HARQ) process of the first terminal;
When the sidelink HARQ feedback is activated, the sidelink HARQ feedback information for the sidelink signal transmitted from the first terminal to the second terminal is received from the second terminal through the transceiver,
Reporting the received sidelink HARQ feedback information to the base station through the transceiver,
in response to the report, at least one processor for starting a sidelink HARQ round trip time (RTT) timer associated with the DRX;
A first terminal comprising a.
10. The method of claim 9,
the at least one processor,
When the sidelink resource is a resource for new transmission of the sidelink signal, the first terminal starts an inactivity timer related to the DRX
.
10. The method of claim 9,
the at least one processor,
When the sidelink HARQ feedback is not activated, based on a preset value related to the retransmission of the sidelink signal, identify whether to retransmit the sidelink signal;
When it is identified that retransmission of the sidelink signal is required, the first terminal starts a sidelink retransmission timer related to the DRX.
12. The method of claim 11,
The DRX-related sidelink retransmission timer indicates a maximum time until the first terminal acquires a resource allocated for retransmission of the sidelink signal,
The DRX-related sidelink retransmission timer is a first terminal driven for each sidelink HARQ process of the terminal.
13. The method of claim 12,
the at least one processor,
When the first terminal acquires the resource allocated for retransmission of the sidelink signal, the first terminal stops the sidelink retransmission timer related to the DRX
.
10. The method of claim 9,
The DRX-related sidelink HARQ-RTT timer indicates the minimum time required for the base station to process the report on the sidelink HARQ feedback information transmitted by the first terminal,
The DRX-related sidelink HARQ-RTT timer is a first terminal driven for each sidelink HARQ process of the terminal.
10. The method of claim 9,
The active time associated with the DRX is,
A first terminal including a period during which the scheduling request for the sidelink is transmitted to the base station on a physical uplink control channel (PUCCH).

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